Flavius Josephus, The Wars of the Jews
William Whiston, A.M., Ed.

[370] So now the last hope which supported the tyrants, and that crew of robbers who were with them, was in the caves and caverns under ground; whither, if they could once fly, they did not expect to be searched for; but endeavored, that after the whole city should be destroyed, and the Romans gone away, they might come out again, and escape from them. This was no better than a dream of theirs; for they were not able to lie hid either from God or from the Romans. However, they depended on these under-ground subterfuges, and set more places on fire than did the Romans themselves; and those that fled out of their houses thus set on fire into the ditches, they killed without mercy, and pillaged them also; and if they discovered food belonging to any one, they seized upon it and swallowed it down, together with their blood also; nay, they were now come to fight one with another about their plunder; and I cannot but think that, had not their destruction prevented it, their barbarity would have made them taste of even the dead bodies themselves.